The war for iron
Researchers at the University of Utah have found that primates – including various monkeys and even humans – have been locked in an evolutionary battle with infectious bacteria over iron, a trace element found in our bloodstream. Both primates and bacteria need iron, and the researchers discovered that part of our immune response against infectious bacteria is to starve them of iron. To do so, transferrin, the protein that transports iron in the blood, masks the element so that bacteria cannot get to it. However, several bacteria have developed proteins of their own that can ‘steal’ iron from transferrin. This struggle for iron is between pathogens and our immune system explains a mutation in the transferrin gene in about 25% of the world’s population, which had previously baffled scientists. We now know that this mutation is an innovation in the ‘war for iron’ between bacteria and humans.